blkcg: remove unused @pol and @plid parameters

@pol to blkg_to_pdata() and @plid to blkg_lookup_create() are no
longer necessary.  Drop them.

Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4fdeb46..55ccbae 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -568,7 +568,6 @@
 
 struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,
 				       struct request_queue *q,
-				       enum blkio_policy_id plid,
 				       bool for_root)
 	__releases(q->queue_lock) __acquires(q->queue_lock)
 {
@@ -1027,7 +1026,7 @@
 	rcu_read_lock();
 
 	spin_lock_irq(disk->queue->queue_lock);
-	blkg = blkg_lookup_create(blkcg, disk->queue, plid, false);
+	blkg = blkg_lookup_create(blkcg, disk->queue, false);
 	spin_unlock_irq(disk->queue->queue_lock);
 
 	if (IS_ERR(blkg)) {